Safety ski binding

Abstract

A safety ski binding which includes a cable interconnecting a ski boot or plate attached to a ski boot with the ski. A restoring spring is provided which forces the cable toward a position holding the ski boot in an in-use skiing position on the ski, while permitting relative movement of the boot and ski and consequent extension of the cable. To prevent serious injuries in the case of full extension of the cable, the cable is disconnected, thereby fully separating the ski and boot. In preferred embodiments, a ski brake is provided to brake the separated ski.

We claim: 
     
       1. A safety ski binding comprising: extensible line means for interconnecting a ski boot and a ski,   restoring force means acting on said extensible line means to force said extensible line means toward a position holding the ski boot in an in-use position on the ski while permitting relative movement of the boot and ski caused by skiing forces, accompanied by extension of the extensible line means which remains connected between the boot and ski to assure return of the boot to its in use skiing position upon cessation of the skiing forces,   and disconnecting means for automatically disconnecting the extensible line means from one of the ski boot and ski to separate the ski and ski boot in response to extension of the extensible line means beyond a predetermined maximum amount.   
     
     
       2. A safety ski binding according to claim 1, further comprising: ski brake means movable between non-braking and braking positions,   ski brake holding means for holding said ski brake means in said non-braking position when said extensible line means interconnects said ski boot and ski,   and ski brake activating means for moving said ski brake means to said braking position in response to disconnection of said extensible line means by said disconnecting means.   
     
     
       3. A safety ski binding according to claim 2, wherein the disconnecting means includes means for simultaneously releasing the ski brake when disconnecting the extensible line means. 
     
     
       4. A safety ski binding according to claim 3, wherein a slide member operates a lever for releasing the ski brake in the case of complete extension of the extensible line means. 
     
     
       5. A safety ski binding according to claim 3, wherein the extensible line means includes an extensible cable, and wherein the releasing means releases the ski brake in response to full extension of said cable. 
     
     
       6. A safety ski binding according to claim 1, comprising a sole plate, boot hold-down means for holding the boot on the sole plate,   and sole plate hold-down means for holding the sole plate on the ski,   wherein said extensible line means connects the sole plate to the ski, and wherein said disconnecting means includes releasing means for releasing one of said boot hold-down means and said sole plate hold-down means in response to said extension of the extensible line means beyond a predetermined amount.   
     
     
       7. A safety ski binding according to claim 6, wherein the extensible line means includes a cable and wherein a plunger extendable by the cable is arranged in a longitudinally displaceable manner in a longitudinal groove of the plate, said plunger being prestressed by a spring in any normal position in which the plate is held on the ski, said plunger simultaneously forming the releasing means. 
     
     
       8. A safety ski binding according to claim 7, wherein, in the vicinity of the end of the longitudinal groove, the boot hold-down means includes a movable shoulder prestressed in the holding direction by a spring which projects into the groove to be engaged by the plunger. 
     
     
       9. A safety ski binding according to claim 8, wherein the boot hold-down means is arranged on the sole plate and is detachably held down by said shoulder, and wherein said boot hold-down means pivots about a transverse axis and optionally about a vertical axis. 
     
     
       10. A safety ski binding according to claim 6, wherein the extensible line means includes a cable drum fixed to the sole plate which is prestressed in the winding-on direction by a spring, wherein the cable of the cable drum is fixed to the ski, and wherein the releasing means releases said boot hold-down means when the cable is fully extended. 
     
     
       11. A safety ski binding according to claim 10, wherein a projection is provided on the cable drum which, when the cable is fully extended, operates a locking lever prestressed in the locking direction and which releases the boot hold-down means. 
     
     
       12. A safety ski binding according to claim 11, wherein the boot hold-down means is constructed as a holding device whereon engages the locking lever and which pivots about a transverse axis and preferably about a vertical axis. 
     
     
       13. A safety ski binding according to claim 10, wherein a locking lever which when operated releases the boot hold-down means is provided and which is connected with the ski via an extensible unlocking member in such a way that when the cable is fully extended, the unlocking member is stretched and throws the locking lever into its release position. 
     
     
       14. A safety ski binding according to claim 13, wherein the unlocking member is a helically wound grappling cable. 
     
     
       15. A safety ski binding according to claim 10, wherein the boot hold-down means includes a toggle-joint holding down device connected to an extensible unlocking member, and wherein the other end of the unlocking member is fixed to the ski in such a way that with the cable fully extended the unlocking member is stretched and the toggle-joint holding-down device is opened. 
     
     
       16. A safety ski binding according to claim 10, wherein the drum has a variable diameter in such a way that the winding diameter increases with increasing winding-off, in such a way that the increasing force of the restoring spring is compensated or over-compensated. 
     
     
       17. A safety ski binding according to claim 16, wherein the drum has a spiral shape. 
     
     
       18. A safety ski binding according to claim 16, wherein the boot hold-down means includes a toggle-joint holding down device connected to an extensible unlocking member, and wherein the other end of the unlocking member is fixed to the ski in such a way that with the cable fully extended the unlocking member is stretched and the toggle-joint holding-down device is opened. 
     
     
       19. A safety ski binding according to claim 6, wherein the releasing means releases the sole plate hold-down means in response to said extension of the extensible line means beyond a predetermined amount. 
     
     
       20. A safety ski binding according to claim 19, wherein the sole plate is connected with an intermediate plate by said extensible line means, which intermediate plate is in turn detachably held on the ski, said releasing means releasing said intermediate plate together with said sole plate in response to said extension of the extensible line means beyond a predetermined amount. 
     
     
       21. A safety ski binding according to claim 20, wherein the restoring force means is arranged in the intermediate plate. 
     
     
       22. A safety ski binding according to claim 6, in which the extensible line means includes an extendable cable, wherein said releasing means disconnects one of the cable ends from its mounting in the case of full extension of said cable. 
     
     
       23. A safety ski binding according to claim 22, wherein a slide member spring-loaded by a spring is arranged in a longitudinal groove provided in one of the sole plate, an intermediate plate disposed between the sole plate and the ski, the ski, and the ski boot, whereby said slide member can enter into a tension-transmitting engagement via a latch with a swivel fixed to the end of the cable, but is separated from the swivel in the case of complete cable extension. 
     
     
       24. A safety ski binding according to claim 22, wherein the extensible line means and restoring force means are automatically locked in the released state upon said automatic disconnection and only after eliminating this state are they again freed for retraction. 
     
     
       25. A safety ski binding according to claim 6, in which said extensible line means includes a cable drum spring-pretensioned in the winding-on direction and arranged on one of the sole plate and the ski, wherein the drum side cable end is terminated by a swivel which is radially inserted in a fitting recess. 
     
     
       26. A safety ski binding according to claim 25, wherein the cable drum cooperates with a spring-loaded latch which snaps in when the cable is fully extended and secures the cable drum against reversing. 
     
     
       27. A safety ski binding according to claim 26, wherein a locking device is provided for the latch which only frees the latch for manual release when the cable end has again been fitted in the drum. 
     
     
       28. A safety ski binding according to claim 25, wherein the extensible line means and restoring force means are automatically locked in the released state upon said automatic disconnection and only after eliminating this state are they again freed for retraction. 
     
     
       29. A safety ski binding according to claim 28, wherein the cable drum cooperates with a spring-loaded latch which snaps in when the cable is fully extended and secures the cable drum against reversing. 
     
     
       30. A safety ski binding according to claim 25, wherein the drum has a variable diameter in such a way that the winding diameter increases with increasing winding-off, in such a way that the increasing force of the restoring spring is compensated or over-compensated. 
     
     
       31. A safety ski binding according to claim 6, wherein the extensible line means and restoring means are automatically locked in the release state upon said automatic disconnection and only after eliminating this state are they again freed for retraction. 
     
     
       32. A safety ski binding according to claim 6, further comprising: ski brake means movable between non-braking and braking positions,   ski brake holding means for holding said ski brake means in said non-braking position whenever said extensible line means interconnects said ski boot and ski,   and ski brake activating means for moving said ski brake means to said braking position in response to disconnection of said extensible line means by said disconnecting means.   
     
     
       33. A safety ski binding according to claim 32, wherein said releasing means releases the sole plate hold-down means in response to said extension of the extensible line means beyond a predetermined amount.